BIOLOGU QUIZ UNIT 3

Question 1

What is a tetrad?

Answer 1

two pairs of homogolous chromosomes next to eachother

(overlap of chromosome before crossing over)

Question 2

What did mendel do?

Answer 2

establishing the fundamental principles of inheritance through his experiments with pea plants. He discovered that traits are passed down through discrete factors, now known as genes, and that these factors can be dominant or recessive. Mendel’s work led to the formulation of the laws of segregation and independent assortment, which form the basis of Mendelian genetics.

Question 3

What is locus?

Answer 3

Locus is a specific location of a gene on a chromosome

Question 4

What is Homozygous dominant

Answer 4

having two dominant alleles (BB)

Question 5

What is Homozygous recessive?

Answer 5

Having two recessive alleles

Question 6

What is heterozygous

Answer 6

having two diffeent alleles for a specific trait (Bb or bB)

Question 7

What is homologous?

Answer 7

Chromosomes that are the same in structure, size, gene sequence, ect.

Question 8

What is stem cell differentiation?

Answer 8

the process by which an unspecialized stem cell transforms into a more specialized cell type, like a muscle cell or blood cell

Question 9

Explain how stem cells can produce a variety of specialized cells.

Answer 9

through the process of differentiation

Question 10

Explain nondisjunction and describe conditions that it might cause.

Answer 10

the failure of the chromosomes to separate which produces daughter cells with abnormal numbers of chromosomes (leads to down syndrome)

Question 11

Be able to compare and contrast mitosis and meiosis.

Answer 11

Mitosis:
- produces two identical daughter cells from one parent cell,
- essential for growth and repair.

Meiosis:
- generates four genetically diverse gametes (sperm and egg) from a single parent cell,
- crucial for sexual reproduction and introducing genetic variation.

Question 12

Explain how chromosomes divide during the formation of egg and sperm cells.

Answer 12

During meiosis, chromosomes divide in a specialized way to reduce the number of chromosomes by half, resulting in gametes (sperm and egg cells) with a single set of 23 chromosomes.

Question 13

Explain the social controversy over embryonic stem cells.

Answer 13

Explain the social controversy over embryonic stem cells.

Question 14

What is incomplete dominance?

Answer 14

Where neither allele in a pair completely masks the other ( red flower + white flower = pink flower)

Question 15

What is codominance?

Answer 15

both alleles for a trait are expressed ( red flower + white flower = red petaled and white petaled flower )

Question 16

What are multiple alleles?

Answer 16

situations where a gene has more than two alleles within a population (ex: blood types)

Question 17

What are polygenic traits?

Answer 17

characteristics (phenotypes) influenced by multiple genes, rather than a single gene, and often by environmental genes as well.

Question 18

Explain alternative inheritance patterns.

Answer 18

patterns where traits do not follow the simple dominant/recessive rules of Mendelian inheritance. These patterns include incomplete dominance, codominance, multiple alleles, polygenic inheritance, and the influence of the environment on gene expression.

Question 19

Explain how a rice crop can be genetically engineered.

Answer 19

The gene from daffodil or corn (maize) is inserted into the rice.
- modified to produce beta-carotene

Question 20

Explain how genes and chromosomes behave during meiosis and sexual reproduction.

Answer 20

the combination of genes and chromosomes is shuffled and reduced in number through a special type of cell division called meiosis, leading to genetic variation in offspring.

Question 21

What is the prophase in meiosis 1 and 2:

Answer 21

1:
The longest phase of meiosis where chromosomes pair up and cross over

2. The sister chromatids condense further

Question 22

What is metaphase in meiosis 1 and 2:

Answer 22

1: Paired chromosomes line up in the middle of the cell

2: Chromosomes (each with two sister chromatids) line up in the middle of the cell.

Question 23

What is Anaphase in meiosis 1 and 2:

Answer 23

1: Paired chromosomes line up in the middle of the cell

2: Sister chromatids separate, moving to opposite ends of the cell.

Question 24

What is Telophase in meiosis 1 and 2:

Answer 24

1: Two new nuclei form, and the cell divides into two haploid daughter cells.

2: Two new nuclei form, and the cell divides into two haploid daughter cells

Question 25

Compared to the number of chromosomes contained in a body cell of a parent, how many chromosomes would normally be contained in a gamate?

Answer 25

Half as many

Question 26

One reason for Mendel's success with genetic studies of garden peas was that he..

Answer 26

studied large numbers of offspring

Question 27

All the heritable genes found in a population constitute the population's:

Answer 27

gene pool

Question 28

Which concept was proposed by Mendel?

Answer 28

independent assortment

Question 29

Two genes are linked if they are..

Answer 29

located on the same chromosomes

Question 30

Pairs of genes that control the same trait are known as

Answer 30

alleles

Question 31

Allelic pairs of genes are located only..

Answer 31

on homologous pairs of chromosomes

Question 32

Mendels discovery that characteristics are inherited due to the transmission of hereditary factors resulted from his

Answer 32

analysis of the offspring produced from many pea plant crosses

Question 33

In humans there are 23 pairs of chromosomes. One pair of the 23 are sex chromosomes. The other 22 pairs are known as..

Answer 33

autosomes

Question 34

Asexual reproduction of diploid organisms normally results in new organism that contain cells with

Answer 34

the 2n number of chromosomes (2x the number) (2x (no gametes since asexual)

Question 35

What is the definition of the term "gene"?

Answer 35

a sequence of nucleotides that directs the synthesis of a product, such as a protein

Question 36

Homologous pairs of chromosomes are restored as a result of

Answer 36

fertilization

Question 37

The frequency of traits which presently offer high adaptive value to a population may decrease markedly in future generation if..

Answer 37

the environment changes

Question 38

Which is the result of normal meiosis and fertilization in humans?

Answer 38

new gene combinations

Question 39

The chances of a YY chromosome combination occurring in humans as a result of normal meiotic division and normal gametic fusion is... A. 0% B. 25% C. 50% D. 100%

Answer 39

A. 0%

Question 40

Some studies of identical human twins show that their IQ, height, and talents, may be different. The best explanation for these differences is that..

Answer 40

the environment with genes in the development and expression of inherited traits.

Question 41

The egg cells of a species are most similar to the sperm cells of that species in their

Answer 41

chromosome number

Question 42

What is the normal number of chromosomes in a human zygote?

Answer 42

24

Question 43

The formation of a tetrad during meiosis occurs as a result of..

Answer 43

synapsis

Question 44

What is synapsis?

Answer 44

the pairing of homologous chromosomes during meiosis

Question 45

Hereditary information for most traits is generally located in ...

Answer 45

genes found on chromosomes

Question 46

A human male will normally transmit the genes on his X-chromosome to...

Answer 46

his daughters, only

Question 47

A diploid cell of a normal human male contains

Answer 47

22 pairs of autosomes, one X-chromosome, and one Y-chromosome

Question 48

A human zygote is produced from two gametes that are identical in..

Answer 48

chromosome

Question 49

What is the difference between a stem cell and a differentiated cell, such as a red blood cell?

Answer 49

The difference between a stem cell and a differentiated cell is that stem cells can turn into differentiated cells and can make copies of itself. Differentiated cells have a more specific function and they can only make copies of their own type, not other cell types.

Question 50

Explain the difference between simple dominance, incomplete dominance, and codominance.

Answer 50

The difference between simple dominance, incomplete dominance, and codominance is that simple dominance happens when of the two traits, one is recessive and one is dominance, this term is called heterozygous. Incomplete dominance is the difference in that neither trait is dominant. If an organism happens to be heterozygous, the trait will be a blend of or intermediate of the two. In codominance, a heterozygous organism will express phenotype of both traits.

Question 51

When an organism is genetically modified, what is changed?

Answer 51

the genotype and phenotype of the organism.

Question 52

How do the daughter cells that result from meiosis compare to the parent cell?

Answer 52

Daughter cells that result from meiosis are half (50%) identical to the parent cell.

Question 53

Explain how crossing over can affect the genetic makeup of the gametes and organism produces

Answer 53

Crossing over can affect the genetic makeup of the gametes and organism produced by increasing the possibility of new gene combinations forming which increases gene variation.

Question 54

A salmon is genetically modified in a laboratory by inserting one gene into one chromosome of a pair. The salmon escapes, and breeds with a wild, unmodified salmon. Would you expect all of the offspring to be genetically modified? Explain your reasoning

Answer 54

No, because when a genetically modified organism mates with a wild organism, you only have a 50% chance of spreading the genetic modification to each of the offspring. This is because in meiosis daughter cells that result from meiosis are half (50%) identical to the parent cell.

Question 55

Explain the relationship between genes, chromosomes, and DNA.

Answer 55

DNA carries the genetic information in our body, but that's not all it carries. DNA is wrapped with proteins into structures called chromosomes. Genes are segments of DNA which carry genetic information which influence the traits of our body. Chromosomes carry DNA and carry genes which hold the genetic information.

Question 56

How does the number of chromosomes in gametes of an organism that reproduces sexually differ from the number of chromosomes in its other cells? Explain.

Answer 56

Gametes are haploids, meaning it has half the number of chromosomes than other cells. Other cells are diploids meaning they have double the amount of chromosomes haploids which differs from gametes to other cells.