LEARNER'S CORNER

 STRANGE FACTS ABOUT HUMAN BODY

1. The average person produces enough saliva in their lifetime to fill 2 swimming pools.

2. Every 60 seconds, your red blood cells do a complete circuit of your body.

3. Most babies are born with blue eyes; exposure to UV light brings out their true color.

4. It can take your finger and toenails 1/2 a year to grow an entirely new nail (from base to tip).

5. The muscles that control your eyes contract about 100,000 times a day (that's the equivalent of giving your legs a workout by walking 50 miles). 

6. Over the course of your lifetime, you'll shed about 40lbs of skin.

7. Your brain uses about 20% of your oxygen and caloric intake.

8. In each kidney, there are 1 million filters that clean around 1.3 liters of blood every minute and push out close to 1.5 liters of urine every day.

9. Ovaries contain over 500,000 eggs, but only about 400 get the opportunity to create life.

  

FUN SHEET-TRANSPORT IN PLANTS

Go through the link given below and thereafter attempt the fun sheet that follows:

http://www.learnnext.com/nextgurukul/wiki/concept/CBSE/VII/Science/Transportation-in-Plants.htm

Problem 1.

How is water transported in plants?

Materials

• 3-4 Water Glasses
• Water
• Food colour
• 3 or 4 fresh white carnations
• Ruler
• Sharp knife
• Cutting board

Procedure

1. Fill each of the three water glasses with a half cup of water.
2. Add twenty drops of food colour
3. Stir the food colour into the water.
4. Ask a grown-up to help you cut the last centimetre off the white carnation. You should cut the stem at a 45 degree angle.
5. Immediately put the flower in the food colour.
6. Do not disturb the flowers. Observe them after 2, 4, 8, 24, and 48 hours, paying special attention to the bottom of the stems.
7. If desired, cut 4 or so centimetres off the stem of one of the finished flowers to observe it more closely.

Record your observations and give possible reasons for the observations.

Problem 2.

To explain the role of xylem vessels and transpiration in the movement of water in a plant body.

Procedure

Write a short passage (around 100 words) explaining how water moves through a plant, highlighting the role of xylem vessels. (It may be easiest to start with transpiration from

the leaves.) 

 Questions on Human Reproductive System

1.What is false?
(a) Menarche is beginning of menstruation
(b) Menstruation is shedding of endometrial lining
(c) Menopause occurs in the beginning of puberty
(d) Ovulation occurs under high tire of LH

2. Various parts of male urethra are
(a) Prostatic, bulbourethra and ejaculatory
(b) Prostatic, membranous and penile
(c) Corpora cavernosa and corpus spongiosum
(d) Prostatic, bulbourethal and glans

3.Types of asexual reproduction found in hydra is
(a) Sporulation
(b) Gemmule formation
(c) Bianry fission
(d) Budding

4.Type of cleavage that occurs in human zygote
(a) Holoblastic and equal
(b) Holoblastic and unequal
(c) Meroblastic
(d) Meroblastic and superficial

5. Twins joined in various regions are
(a) Fraternal twins
(b) Identical twins
(c) Siamese twins
(d) non-identical twins

6. Thick layer which immediately surrounds the ovum is
(a) Zona pellucida
(b) Membrana granulosa
(c) Corona radiata
(d) vitelline membrane

7. The single layer of germinal epithelium covering the ovary is composed of
(a) squamous cells
(b) cuboidal cells
(c) columnar cells
(d) none of the above

8. The shortest phase in menstrual cycle is
(a) Menstrual phase
(b) Secretory phase
(c) Ovulatory phase
(d) Proliferative phase

9. The sense organs are developed from
(a) ectoderm
(b) mesoderm
(c) endoderm
(d) different germ layers

10. The role of sertoli cells in spermatogenesis is
(a) they direct morphogenesis of sperms
(b) they provide nutrition to developing sperms
(c) both a and b
(d) they stimulate germinal epithelium

11. The role of Leydig cells is
(a) Nourishment of sperms
(b) Give motility to sperms
(c) Synthesize testosterone hormone
(d) Undergo spermatogenesis

12. The path, where male nucleus fuses with female pronucleus, is known as
(a) Fertilization path
(b) Penetration path
(c) Copulation path
(d) none of the above

13. The morula is formed during cleavage after
(a) 2 days of fertilization
(b) at the end of third day of fertilization
(c) 4 days after fertilization
(d) 7 days of fertilization

14. The membrane which holds ovary in position is called
(a) mesorchium
(b) mesovarium
(c) parietal peritoneum
(d) mesosalpinx

15. The lytic enzyme released by sperm is
(a) Acrosome
(b) Ligase
(c) Androgenase
(d) Hyalouronidase

16. The length of tube in the epididymis of a testis is
(a) 3 meters
(b)  meters
(c) 5 meters
(d) 6 meters

17. The internal cavity commonly formed by cell division prior to gastrulation is
(a) Enteron
(b) Blastopore
(c) Blastocoel
(d) Coelom

18. The hormone responsible for maintaining the pregnancy is
(a) LH
(b) FSH
(c) Progesterone
(d) Oestrogen

19. The head of mature mammalian sperm is made of
(a) An acrosome
(b) Elongated nucleus covered by acrosome
(c) Two centrioles and an aial filament
(d) Nucleus, acrosome, cytoplasm and mitochondrial sheath

20. The gravid phase of uterus is
(a) proliferative phase
(b) ovulatory phase
(c) secretary phase
(d) none of the above

WORKSHEET ON MUTATIONS

There are three main types of mutations: point missense mutations, point nonsense mutations, and frameshift mutations.  In each of the following DNA sequences, you will use the mRNA and amino acid sequences to identify the mutation that occurred and the effects of each on, if any.  Look and analyze carefully!

Original DNA Sequence:     T  A  C  A  C  C  T  T  G  G  C  G  A  C  G  A  C  T mRNA Sequence:             AUG  UGG                                                                        Amino Acid Sequence:

Mutated DNA Sequence #1: T  A  C  A  T  C  T  T  G  G  C  G  A  C  G  A  C  T What’s the mRNA sequence? (Circle the change)                                                                                                       What will be the amino acid sequence?                                                                                                                        Will there likely be effects?                              What kind of mutation is this?

Mutated DNA Sequence #2: T  A  C  G  A  C  C  T  T  G  G  C  G  A  C  G  A  C  T What’s the mRNA sequence? (Circle the change)                                                                                                       What will be the amino acid sequence?                                                                                                                        Will there likely be effects?                              What kind of mutation is this?

Mutated DNA Sequence #3: T  A  C  A  C  C  T  T  A  G  C  G  A  C  G  A  C  T What’s the mRNA sequence? (Circle the change)                                                                                                       What will be the amino acid sequence?                                                                                                                        Will there likely be effects?                              What kind of mutation is this?

Mutated DNA Sequence #4: T  A  C  A  C  C  T  T  G  G  C  G  A  C  T  A  C  T What’s the mRNA sequence? (Circle the change)                                                                                                       What will be the amino acid sequence?                                                                                                                        Will there likely be effects?                              What kind of mutation is this?

Mutated DNA Sequence #1: T  A  C  A  C  C  T  T  G  G  G  A  C  G  A  C  T What will be the corresponding mRNA sequence?                                                                                                      What will be the amino acid sequence?                                                                                                                        Will there likely be effects?                              What kind of mutation is this?

  
MNEMONICS FOR BIOLOGY

Mnemonic device

"Idiot, Please Carry Everyones Biology Book"

Explanation

ECOLOGY: SMALLEST TO BIGGEST
Idiot = Individual
Please = Population
Carry = Community
Everyones = Ecosystem
Biology = Biome
Books = Biosphere

Mnemonic device

"Old People Catch Easy Breaks"

Explanation

These are the five levels at which relationships between biotic/abiotic factors are studied.
Old = Organisms
People = Populations
Catch = Communities
Easy = Ecosystems
Breaks = Biosphere

Mnemonic device

"Some Grownups Can't See Magic Ponies But Children CAN"

Explanation

Classes and sub-classes of Phylum Mollusca:
S = Scaphopoda
G = Gastropoda
C = Caudofoveata
S = Solenogastres
M = Monoplacophora
P = Polyplacophora
B = Bivalvia
C = Cephalopodia
CAN = (sub-classes of Cephalopodia) Coleoids, Ammonoids, and Nautiloids

Mnemonic device

"All Have Calcerous Osscile Endoskeleton"

Explanation

Five classes of Echinoderms:
Asteroidea (All)
Holothuroidea (Have)
Crinoidea (Calcerous)
Ophiuroide (Ossicle)
Echinoidea (Endoskeleton)
Other than tetraradial symmetry, the calcerous ossicle endoskeleton is the only characterisitic shared by all 5 classes of this Phylum.

Mnemonic device

"GRIM END"

Explanation

The 7 aspects of life:
Growth, Reproduction, Irritability, Movement, Excretion, Nutrition, and Death

Mnemonic device

"CORD 'N' GERMS"

Explanation

Characteristics of Life:
Cells, Osmoregulation, Reproduction, Death, Nutrition, Growth, Excretion, Respiration, Movement, and Sensitivity.

Mnemonic device

"MRS GREN"

Explanation

The common attributes of living things:
Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, and Nutrition.

Mnemonic device

"Count Every Blockhead Acquiring My Amphibians"

Explanation

The six stages of fertilization (in order):
Contact, Entry, Blocks to polyspermy, Activation of cell, restart of Meiosis, and Amphimixis.

Mnemonic device

"At The Girl's Club"

Explanation

Base Pairing:
At The Girl's Club = AT + GC
Adenine pairs with Thymine
Guanine pairs with Cytosine

Mnemonic device

"German MADE"

Explanation

Types of Immunoglobulins:
IgG, IgM, IgA, IgD, and IgE

Mnemonic device

"ACTH"

Explanation

Adrenal gland functions:
Adrenergic functions
Catabolism of proteins/ Carbohydrate metabolism
T cell immunomodulation
Hyper/ Hypotension (blood pressure control)

Mnemonic device

"Adaxial and Abaxial: the two surfaces of a leaf"

Explanation

aBaxial is the Bottom and aDaxial is Da' Top.

Mnemonic device

"STARK"

Explanation

Vaccines Types:
Subunit
Toxoid
Attenuated [live]
Recombinant
Killed [inactivated]

Mnemonic device

"Fight or Flight" and "Rest and Digest"

Explanation

Parasympathetic vs. sympathetic function
Sympathetic nervous system: "Fight or Flight".
Parasympathetic nervous system: "Rest and Digest".

Mnemonic device

"RoD and Cones"

Explanation

Rods vs. cone function
RoD: Dim light.
Cones: Color.

Mnemonic device

"a KINd AuNT"

Explanation

KINesin for ANTerograde transport.

Mnemonic device

"The Strong Man’s Triceps Explode"

Explanation

The order of the earth’s atmosphere:
Troposphere, Stratosphere, Mesosphere, Thermosphere, and Exosphere.

Mnemonic device

"Old People From Texas Eat spiders"

Explanation

The bones of the skull:
Occipital, Parietal, Frontal, Temporal, Ethnoid, and Sphenoid.

Mnemonic device

"OILRIG"

Explanation

Oxidation Is Loss
Reduction Is Gain

Mnemonic device

"Must Be God/Good"

Explanation

Stages in Development:
Morula, Blastula, and Gastrula.

Mnemonic device

"CEVASACK"

Explanation

Vertebrate Features:
Cephalization, Endoskeleton, Vertebrae, Axial Skeleton, Skull, Appendicular skeleton, Closed circulatory system, Kidneys, and White Blood Cells (in decreasing order of numbers).

Mnemonic device

"SAME DAVE"

Explanation

Spinal cord nerve origins:
Sensory - Afferent
Motor - Efferent
Dorsal - Afferent
Ventral - Efferent

Mnemonic device

"never MIS (or) MIS"

Explanation

Inner Ear Bones:
Maleus, Incus, and Stapes.

Mnemonic device

"Turn Pike Many Accidents"
"Try Pulling My Aorta"

Explanation

The Heart Valves:
Tricuspid, Pulmonic, Mitral, and Aortic.

Mnemonic device

"tRIcuspid valve"

Explanation

tRIcuspid valve is on the RIght side of the heart.

Mnemonic device

"SKILL"

Explanation

Excretory Organs of the Body:
Skin, Kidneys, Intestines, Liver, and Lungs.

Mnemonic device

"Old Charlie Foster Hates Women Having Dull Clothes"

Explanation

Functions of Blood:
Oxygen (transport), Carbon Dioxide (transport), Food, Heat, Waste, Hormones, Disease, and Clotting.

Mnemonic device

"Sir, I'm nervous about reproducing with the rest. Uri must dig into the end"

Explanation

Organ Systems:
Circulatory, Immune, Nervous, Reproduction, Respiratory, Urinary, Muscle, Digestive, Integumentary and Endocrine.

Mnemonic device

"FOr Very Acute Vision"

Explanation

Eye:
Fovea, the part of the retina most densely packed with cones.

Mnemonic device

"Rods protected by a Gang of Lions and Polar Bears"

Explanation

Cells of the Retina:
Rods, cones, ganglion, and polar bodies.

Circulatory System-Fun sheet

Top of Form

What is the circulatory system?

The body's breathing system

The body's system of nerves

The body's food-processing system

The body's blood-transporting system

From what source do cells get their food?

Blood

Oxygen

Other cells

Carbon dioxide

Why is oxygen important to blood and to the cells?

	Oxygen helps the blood to clot.
	Oxygen brings food to the cells.
	Oxygen is necessary for cell growth and energy.
	Oxygen is not important -- carbon dioxide is the most important substance to the body.

Which type of blood vessels carries blood away from the heart?

Veins

Arteries

Capillaries

Arteries, veins and capillaries

Why is blood that flows from the lungs to the heart bright red rather than dark red?

	Oxygen makes it red.
	Carbon dioxide makes it red.
	Gastric juices produce the red colour of the blood.
	The lungs add a pigment (dye) to blood as it flows through them.

What part of the blood carries minerals, vitamins, sugar, and other foods to the body's cells?

Plasma
Platelets
Red corpuscles
White corpuscles

What is the main job of the red corpuscles in the blood?

	To clot blood
	To fight disease
	To transport oxygen to the body's cells and carry away carbon dioxide from the cells
	To transport carbon dioxide to the body's cells and carry away oxygen from the cells

Which of the following can best be compared to soldiers?

Lungs

Capillaries

Red blood cells

White blood cells

Which element in the blood is round and colourless?

Plasma

Platelets

Red blood cells

White blood cells

What would happen to people who have an open wound and whose blood did not clot naturally?

They would bleed to death.

Nothing. Clotting is not important.

They would have to take special clotting drugs.

They would have to take regular doses of plasma.

What happens when a clot occurred in an undamaged blood vessel?

	You would bleed to death.
	A scab will form on the skin surface.
	Platelets stick to the edges of the cut and to one another, forming a plug.
	The flow of blood to tissues beyond the clot may be cut off.

What happens to blood when it is pumped into the thin-walled blood vessels of the lungs?

	Platelets are exchanged for plasma.
	Carbon dioxide is replaced with oxygen.
	Blood fills the lungs and causes coughing.
	Nothing -- the lungs are just a place blood goes through on its way back to the heart.

What is the function of the blood vessels and capillaries?

	They pump blood to the heart.
	They filter impurities from the blood.
	They carry blood to all parts of the body.
	They carry messages from the brain to the muscles.

Why does blood turn dark red as it circulates through the body?

	It starts to clot.
	It gets old and dirty flowing through the body.
	The oxygen in it is replaced with carbon dioxide.
	The farther blood is from the heart, the more dark red it is.

How many major types of blood have scientists discovered?

One: Type "O"

Two: white cells and red cells

Three: white cells, red cells, and plasma

Four: Types A, B, AB, and O

What is the organ that pumps blood all throughout the human body?

The lungs

The heart

The kidneys

The blood vessels and capillaries

MCQs  – Animal Nutrition

1.Nutrients absorbed into the blood of intestinal villi goes to

a. Aorta

b. Precaval vein

c. Hepatic portal vein

d. Hepatic artery

2. Brunner’s glands are present in

a. Oesophagus

b. Duodenum

c. Ileum

d. Stomach

3. Enamel is secreted by

a. Dentoblasts

b.Odentoblasts

c.Osteoblasts

d.Amyloblasts

4. Which of the following causes contraction of Gall bladder

a. Gastrin

b. Secretin

c. CCK

d. Enterogastron

5. Which Vitamin is synthesised by the Gut bacteria

a.B1

b.C

c.D

d.K

6. Tusk of Elephant is the modified

a. Incisor

b.Canine

c.Premolar

d. Molar

7. Which Vitamin is essential for RBC maturation

a. K

b.B12

c.A

d.C

8. Which element is essential for the maintenance of teeth

a. Zinc

b.Copper

c.Fluorine

d. Manganese

9. Trypsinogen is converted into Trypsin by

a. Enterocrinin

b. Enterokinase

c. Enterogastrin

d. Pancreozymin

10. In Ileum, which substance is absorbed as such

a. Vit.K

b. Bile salts

c. Monosaccharides

d. Proteins

11. Argentaffin cells are found in

a. Pancreas

b.Intestinal glands

c.Gastric glands

d. Liver

12. Arachidonic acid is

a. NEFA

b. PUFA

c. LDL

d. EFA

13. Vitamin D is synthesized in the skin from

a. 7-hydroxy cholesterol

b. Cephanocholesterol

c. Tocopherol

d. Arachidonic acid

14. Secretin hormone is produced from

a. Duodenum

b.Ileum

c.Pancreas

d. Liver

15. Typhlosol of Earthworm is related to

a. Excretion

b. Absorption

c. Respiration

d. Cocoon formation

16. Which Vitamin causes Mineral deposition in the body

a. B12

b. D

c. B1

d. E

17. Vit B2 is used as coenzyme in

a. NAD

b.TPP

c.FMN

d. ATP

18. The shortest part of Human alimentary canal is

a. Pharynx

b.Oesophagus

c. Duodenum

d. Colon

19. The enzyme that has no direct action is

a. Lipase

b.Enterokinase

c. Erepsin

d. Steapsin

20. Intestinal Fauna comprises

a. Acetobactor

b. Clostridium

c. E coli

d. Bacillus

21. The dentition of Frog is

a. Acrodont

b. Thecodont

c.Pleurodont

d. Lophodont

22. Function of Pancreozymin is to control

a. Liver functions

b. Insulin secretion

c. Gall bladder contraction

d. Pancreatic enzyme secretion

23. Which one has no alimentary canal

a. Planaria

b.Tapeworm

c. Liver fluke

d. Ascaris

24. Substance that gives Green colour to Bile is

a. Chlorophyll

b. Breakdown products from Haemoglobin

c. Urochrome from liver

d. Urea

25. Gaucher’s disease to the abnormal metabolism of

a. Fat

b.Protein

c. Carbohydrate

d. Cholesterol

26.The main modes of nutrition gathering in multicellular animals is Photosynthesis, Absorption and Ingestion.  As you know animals Ingest their food.  Animals can be classified further by the kinds of food they eat and the  mechanism of the food they eat.  Which of the following is true.

a)      Herbivores can photosynthesize

b)      Most animals are bulk feeders and include Herbivores, Carnivores and Omnivores

c)      Some herbivores such as aphids can be fluid feeders

d)     Suspension feeders tend to be omnivores, because they  sift small food particles from the water and cannot select their meals

e)      Herbivores tend to be deposit feeders because they wait until the plant is dead to eat it.

27.Multicellular animals that are omnivores use which of the following

a)      After swallowing food the process is called intracellular digestion.

b)      A Gastrovascular cavity is a simple sac in which extracellular digestion can occur

c)      An Alimentary canal can have specialized areas for the  specific treatment of food particles

d)     Only a limited number of cells in the animal body are capable of intracellular digestion and these cells use this process for defense from microscopic organisms rather than nutrition

e)      A gastrovascular cavity is contained within each cell of the alimentary canal in order to maximize surface area and absorb nutrients.

28.The digestive system in an ancient system, so it uses hormones to control the rate and contend to gastric juices produces.  Certain hormones are released from the duodenum by signals within the chyme that is passing through the duodenum.  Which of the following are those hormones

a)      Gastrin that stimulates the stomach to release gastric juice

b)      Secretin that signals the pancreas to release bicarbonate

c)      Cholecystokinin that signals the gall bladder to release bile and the pancreas to release enzymes

d)     Enterogastrone that inhibits peristalsis and slows digestion

e)      Intestine that speeds up peristalsis and increases elimination

29.The uses of food include

a)      energy for body functions

b)      promotes health

c)      raw materials for body function use of carbons, nitrogenous, oxygen etc to build molecules

d)     some nutrients cannot be synthesized in the body like vitamin C in primates and is required in diets

e)      All macromolecules can be broken down and used to make other macromolecules.

30.ascorbic acid (vitamin C) is considered a vitamin in humans yet not in rabbits this is because

a)      humans can make this chemical in the blood

b)      humans cannot make this chemical and it is required in the diet

c)      normal rabbit intestinal flora makes this chemical and it is not a required supplement

d)     rabbits can make this compound in their tissues

e)      humans can make this compound in their tissues

Answer Key

1. c

2. b

3. b

4. c

5. d

6. a

7. b

8. c

9. b

10. c

11. c

12. b

13. a

14. a

15. b

16. b

17. c

18. a

19. b

20. c

21. a

22. d

23. b

24. b

25. b

26. b,c,d

 27.b,c,d

28. b,c,d

29.a,c,d

30. b,c

Fundamentals of Genetic-Practice Questions

Vocabulary

1. State and define the two laws of heredity.

2. Differentiate self-pollination from cross-pollination.

3. What is the difference between a dominant trait and a recessive trait?

4. Differentiate genotype from phenotype.

5. What is the difference between homozygous and heterozygous?

Multiple Choice Questions

6. A procedure in which an individual of unknown genotype is crossed with a homozygous recessive individual to determine the genotype of the unknown individual is called a (A) monohybrid cross (B) dihybrid cross (C) hybrid cross (D)testcross

7. A gene is a (A) segment of DNA (B) chromosome(C) segment of RNA (D) protein

8. An example of a genotype of a heterozygous individual is (A) pp (B) YY (C) Zz (D) none of the above

9. In a monohybrid cross of two heterozygous parents(Pp), one would expect the offspring to be (A) 1 pp:3 PP (B) 3 Pp: pp (C) 1 PP: 2 Pp; 1 pp (D) all Pp

10. In a monohybrid cross between a homozygous dominant parent and a homozygous recessive parent, one would predict the offspring to be (A) 3:4 homozygous recessive (B) 2:4 homozygous recessive (C) 1:4 homozygous recessive (D) all heterozygous

11. In guinea pigs, black fur is dominant. If a black guinea pig is crossed with a white guinea pig and the litter contains a white offspring, the genotype of the black-haired parent is probably (A) homozygous dominant (B) homozygous recessive (C) pure for the

trait (D) heterozygous dominant

12. Segregation of alleles occurs during (A) mitosis (B) meiosis (C) fertilization (D) pollination

13. In a dihybrid cross between two heterozygous parents, the probability of obtaining an offspring that is homozygous recessive for both traits would be (A) none (B) 9/16 (C) 3/16 (D) 1/16

14. If two parents with dominant phenotypes produce an offspring with a recessive phenotype, then (A) both parents are heterozygous (B) one parent is heterozygous (C) both parents are homozygous (D) one parent is homozygous

15. Suppose that you have found a new species of plant. Some of the plants have red flowers and some have yellow flowers. You cross a red-flowering plant with a yellow-flowering plant, and all the offspring have orange flowers. You might assume that the

alleles for flower color (A) have complete codominance (B) have incomplete dominance (C) are either dominant or recessive (D) have mutated

Short Answer type questions

16. Why did Mendel being his experiments by allowing pea plants to self-pollinate for several generations?

17. In pea plants, purple flower color is dominant over white flower color. Give an example of each of the following:

A. the phenotype of a pea plant heterozygous for flower color

B. the genotype of a pea plant homozygous dominant for flower color

C. the genotype of a pea plant homozygous recessive for flower color

18. Answer the following questions based on the Punnet square shown below:

A. Does the Punnet square demonstrate a monohybrid cross or a dihybrid cross?

B. List the genotypes of the parents

C. Give the genotypic ratio predicted by the Punnet square for the cross

19. Explain the difference between the P generation, F1 generation, and F2 generation.

20. When the dominant and recessive traits are known, why is it not necessary to use the term homozygous when referring to the genotype of an individual with a recessive phenotype?

21. Explain the difference between a monohybrid cross and a dihybrid cross.

22. How might a crossing-over during meiosis affect the segregation of genes on the same chromosome?

23. Relate the events of meiosis to the low of segregation.

24. In pea plants, smooth seed texture is dominant over wrinkled seed texture. A gardener has a pea plant that produces smooth seeds. How can the gardener determine whether the plant is homozygous or heterozygous for the allele that determines seed texture?

25. In rabbits, the allele for black coat color (B) is dominant over the allele for brown coat color (b). Predict the results of a cross between a rabbit homozygous for brown coat color (bb)