Study Guide (Bio midterms):
Structure of Chromosomes, Cell Cycle, Cell Division
1. What are chromosomes?
2. Who discovered chromosomes, in what organism, which
year?
3. What is chromatin made of?(give %)
4. Who first studied the DNA molecule and in which year?
5. Who gave the double helical molecule of DNA and in what
year?
6. Describe the structure of DNA.
7. What are histone proteins?
8. What are nucleosomes?
9. Describe the structure of chromosome.
10. What are chromatids?
11. What are genes?
12. What is a cell cycle?
13. What are the three stages of interphase? Describe
the changes in each stage.
14. Define replication.
15. Define mitosis and meiosis.
16. What are the phases of mitosis?
17. What happens in prophase of mitosis?
18. What happens in metaphase of mitosis?
19. What happens in anaphase of mitosis?
20. What happens in telophase in mitosis?
21. Differentiate between :
i. Cytokinesis and Karyonkinesis
ii. Haploid and Diploid Cells(define and example)
iii. Somatic and Germinal cells(Define and type of
division)
iv. Centrosome and Centromere(Location and function)
v. Mitosis in animal cells and Mitosis in plant cells(mode
of cytokinesis, location, spindle fibres)
vi. Meiosis and Mitosis(where it occurs,what for, when it
occurs, no of daughter cells produced, no of
chromosomes passed, no of nuclear divisions, identity
of daughter cell)
vii. DNA and RNA
22. What is the significance of meiosis?
23. What are homologous chromosomes?
24. What is crossing over?
25. What is chiasma?
GENETICS
1. What is genetics?
2. What is heredity?
3. What is genetic engineering?
4. What is meant by “Like Begets Like”?
5. What are variations?
6. What are characters?
7. What are traits?
8. Give examples of some traits along with their
characters.
9. Define:
i. Karyotype
ii. Autosomes
iii. Sex chromosomes
iv. Genome
v. Dominant Allele
vi. Recessive Allele
vii. Genotype
viii. Phenotype
ix. Pedigree Chart
x. Polydactyly
xi. Camptodactyly
10. Who coined the term gene?
11. What is homozygous dominant and recessive?
12. What is sex linked inheritance?
13. What is X linked inheritance? Give examples.
14. What is Y linked inheritance? Give examples.
15. What is hemophilia?
16. List any 4 dominant and recessive traits in humans
along with their characters.
17. What is law of dominance?
18. What is law of segregation?
19. What is law of independent assortment?
20. Write two characteristics of pea pod with their
alternative traits.
21. What is sickle cell anaemia?
22. Give the common and scientific name of the organism
on which Mendel had worked.
23. In a species of plants, the allele for purple flowers (P)
is dominant over the allele for white flowers (p). If two
heterozygous purple-flowered plants (Pp) are crossed,
what is the expected genotypic and phenotypic ratio of
the offspring?
In humans, having a hitchhiker's thumb (h) is a
recessive trait, while a straight thumb (H) is
dominant. If two parents with straight thumbs,
both heterozygous (Hh), have a child, what is the
probability that the child will have a hitchhiker's
thumb? Use a Punnett square to explain.
In mice, the yellow coat color (Y) is dominant to
gray (y), but the YY genotype is lethal. If two yellow
heterozygous mice (Yy) are crossed, what is the
expected genotypic ratio of the living offspring?
What percentage of the offspring would be yellow?
In snapdragons, the allele for red flowers (R) is
incompletely dominant over the allele for white
flowers (r), resulting in pink flowers (Rr) in
heterozygotes. If a red-flowered plant (RR) is crossed
with a pink-flowered plant (Rr), what are the
expected genotypic and phenotypic ratios of the
offspring?
In guinea pigs, black fur (B) is dominant over brown
fur (b), and short hair (S) is dominant over long hair
(s). If a guinea pig heterozygous for both traits (BbSs)
is crossed with another heterozygous guinea pig
(BbSs), what is the expected phenotypic ratio of the
offspring?
In a certain species of flowers, the allele for tall height
(T) is incompletely dominant over the allele for short
height (t), producing medium height (Tt) in
heterozygotes. Another gene for flower color has red
(R) as dominant over white (r). What are the expected
genotypic and phenotypic ratios if two medium-
height, heterozygous red-flowered plants (TtRr) are
crossed?
In cattle, coat color shows codominance, with red (R)
and white (W) alleles resulting in a roan (RW) coat in
heterozygotes. If a roan cow (RW) is crossed with a
white cow (WW), and we also consider a gene for
horned (H) vs. hornless (h), where horned is
dominant, what are the possible genotypes and
phenotypes of the offspring? Use a Punnett square to
explain.
In humans, color blindness is a recessive X-linked trait
(X^c). A normal-vision woman who is a carrier for
color blindness (X^CX^c) marries a normal-vision man
(X^CY). What are the expected genotypic and
phenotypic ratios of their offspring with respect to
color vision?
In fruit flies, a certain allele for white eyes (w) is
recessive and X-linked. However, when this allele is
present in a homozygous condition in females
(X^wX^w), it is lethal. What is the expected ratio of
living offspring when a heterozygous red-eyed female
(X^WX^w) is crossed with a white-eyed male (X^wY)?
In rabbits, coat color is determined by multiple
alleles. The C allele for full color is dominant over the
c^ch (chinchilla) allele, which in turn is dominant over
the c^h (Himalayan) allele, and the c allele (albino) is
recessive to all other alleles. What are the possible
phenotypes of offspring from a cross between a
rabbit with genotype Cc^h and another with
genotype c^chc? Use a Punnett square to explain.
Height in humans is controlled by multiple
genes(polygenic inheritance). Consider a simplified
model where two genes (A/a and B/b) contribute
additively to height. Each dominant allele contributes
to increased height. If a person with genotype AABb
marries a person with genotype AaBb, what are the
possible genotypes and phenotypes (in terms of
height) of their offspring? Use a Punnett square to
determine the probabilities.
