Lecture 1 Genetics

Question 1

Q: What are the four main ABO blood types?

Answer 1

A: A, B, AB, and O.

Question 2

Why are homologous chromosomes not identical?

Answer 2

They carry different alleles and may have undergone crossing over.

Question 3

What happens during the G1 phase of the cell cycle?

Answer 3

Cell grows and prepares for DNA replication.

Question 4

What is a human karyotype used for?

Answer 4

Identifying chromosomal abnormalities, like trisomy 21.

Question 5

What is the difference between euchromatin and heterochromatin?

Answer 5

Euchromatin is less condensed and transcriptionally active, while heterochromatin is more condensed and generally inactive.

Question 6

What is the outcome of Meiosis I?

Answer 6

A: Two haploid cells, with each chromosome consisting of two sister chromatids

Question 7

How is Meiosis II similar to mitosis?

Answer 7

Both involve the separation of sister chromatids.

Question 8

What is the main difference between meiosis and mitosis in terms of chromosome number?

Answer 8

Meiosis halves the chromosome number (diploid to haploid), while mitosis maintains it.

Question 9

What is the study of Genetics?

Answer 9

The study of the inheritance of observable traits from one generation to the next and their effect on populations and species.

Question 10

Do environmental factors influence ABO blood groups?

Answer 10

No, ABO blood groups show no variation due to environmental factors.

Question 11

Can the expression of a gene be affected by the environment?

Answer 11

Yes, examples include the effect of temperature on fruit fly wing size and rabbit fur color

Question 12

What is the difference between genotype and phenotype?

Answer 12

A: Genotype refers to an organism’s genetic makeup, while phenotype refers to an organism’s physical and biochemical traits.

Question 13

At which chromatin structure level does DNA become transcriptionally inactive?

Answer 13

At the level of the 30 nm chromatin fiber and beyond

Question 14

What is the main purpose of mitosis?

Answer 14

To ensure that an exact copy of the parent cell’s DNA is passed on to the two new daughter cells

Question 15

What is the purpose of meiosis?

Answer 15

To reduce the diploid complement of chromosomes to a haploid complement, producing sex cells (gametes) for sexual reproduction

Question 16

DNA is a ? Stranded
Composed of complementary ? Bases
Joined by ? Bonds
And a ? Backbone

Answer 16

Double stranded molecule
Nitrogenous bases
Joined by Hydrogen bonds
And a deoxyribose + phosphate backbone

Question 17

Homologous Chromsomes describe them.

Answer 17

Same size same shape same structure same length same genes BUT different alleles.

Question 18

Are Sex chromosomes Homolgous and why ?

Answer 18

X/Y are an exception to the Homologous Chromosomes Rule i.e. dont have same length size shape structure or gene but are still considered homologous.

Question 19

What is a karyotype ?

Answer 19

A karyotype is a preparation of the complete set of metaphase chromosomes in the cells of a species or in an individual organism, sorted by length, centromere location and other features.

Question 20

?+?=Chromatin ?

Answer 20

DNA+Histones = Chromatin

Question 21

Rank
Nucleosomes (beads)
30 nm chromatin fiber
Chromatin loops
Sister chromatids
Metaphase chromsome

Answer 21

Nucleosomes
30Nm chromatin fiber
Chromatin loops
Sister chromatids
Metaphase chromsomes

Question 22

Is Genetic material already duplicated at the start of mitosis ?

Answer 22

Yes. It is

Question 23

Does Mitosis include interphase ? What happens during interphase ?

Answer 23

No Mitosis does not include Interphase.
G1- first stage after cell divided.

Cell grows in size and synthesizes mRNA
S- phase -> DNA replication (Chromosomes duplicated , end goal : each chromosome with 2 sister chromatids connected at centromere).
A
G2 -> Check for any damages and prepares for Mitosis and Cytokinesis.

Question 24

What mitotic stage does chromatin start to become distinct chromosomes ?

Answer 24

Prophase

Question 25

What mitotic stage do sister chromatids separate into daughter chromosomes ?

Answer 25

Anaphase

Question 26

What mitotic stage is followed by cytokinesis ?

Answer 26

Telophase

Question 27

2 example of Cells that go through Mitosis

Answer 27

Muscle stem cells
Zygote dividing
Cells of the immune system
Skin cells
Intestinial Epithelial Cells

Question 28

Match the following terms
Haploid , zygote , gamete, Diploid cells, egg , spermatozoon, single cell

Answer 28

Haploid - single cell , gamete
Zygote - Diploid , single cell
Gamete - haploid , single cell
egg - haploid , single cell
spermatozoan - haploid,single cell.