unit 3 dna

Question 1

allele

Answer 1

one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.

Question 2

centromere

Answer 2

the region of a chromosome to which the microtubules of the spindle attach, via the kinetochore, during cell division.

Question 3

chromatid

Answer 3

each of the two threadlike strands into which a chromosome divides longitudinally during cell division. Each contains a double helix of DNA.

Question 4

chromosome

Answer 4

a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

Question 5

codon (chart)

Answer 5

A codon is a DNA or RNA sequence of three nucleotides (a trinucleotide) that forms a unit of genomic information encoding a particular amino acid or signaling the termination of protein synthesis (stop signals).

Question 6

crossing over

Answer 6

one thing crossing over the other

Question 7

daughter cell

Answer 7

Either of the two cells formed when a cell undergoes cell division by mitosis

Question 8

deletion

Answer 8

In genetics, a deletion is a mutation in which a part of a chromosome or a sequence of DNA is left out during DNA replication. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome. Wikipedia

Question 9

diploid

Answer 9

Diploid is a term that refers to the presence of two complete sets of chromosomes in an organism’s cells, with each parent contributing a chromosome to each pair. Humans are diploid, and most of the body’s cells contain 23 chromosomes pairs.

Question 10

DNA

Answer 10

a self-replicating material that is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.

Question 11

fertilization

Answer 11

the action or process of fertilizing an egg, female animal, or plant, involving the fusion of male and female gametes to form a zygote.

Question 12

frameshift

Answer 12

A frameshift mutation is a genetic mutation caused by indels of a number of nucleotides in a DNA sequence that is not divisible by three. Due to the triplet nature of gene expression by codons, the insertion or deletion can change the reading frame, resulting in a completely different translation from the original. Wikipedia

Question 13

gamete

Answer 13

A gamete is a reproductive cell of an animal or plant. In animals, female gametes are called ova or egg cells, and male gametes are called sperm. Ova and sperm are haploid cells, with each cell carrying only one copy of each chromosome.

Question 14

gene

Answer 14

(in informal use) a unit of heredity which is transferred from a parent to offspring and is held to determine some characteristic of the offspring.

Question 15

gene mutation

Answer 15

a change in one or more genes

Question 16

genetic code

Answer 16

Genetic code refers to the instructions contained in a gene that tell a cell how to make a specific protein

Question 17

genetic variation

Answer 17

Genetic variation is a term used to describe the variation in the DNA sequence in each of our genomes. Genetic variation is what makes us all unique, whether in terms of hair colour, skin colour or even the shape of our faces.

Question 18

haploid

Answer 18

Haploid describes a cell that contains a single set of chromosomes. The term haploid can also refer to the number of chromosomes in egg or sperm cells, which are also called gametes.

Question 19

homologous chromosome

Answer 19

Homologous chromosomes are pairs of chromosomes in a diploid organism that have similar genes, although not necessarily identical

Question 20

independent assortment

Answer 20

The Principle of Independent Assortment describes how different genes independently separate from one another when reproductive cells develop.

Question 21

insertion

Answer 21

the action of inserting a extra thing

Question 22

meiosis

Answer 22

a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.

Question 23

meiosis I

Answer 23

During meiosis I, homologous chromosomes first pair with one another and then segregate to different daughter cells

Question 24

meiosis II

Answer 24

Meiosis I is followed by meiosis II, which resembles mitosis in that the sister chromatids separate and segregate to different daughter cells

Question 25

monosomy

Answer 25

Monosomy refers to the condition in which only one chromosome from a pair is present in cells rather than the two copies usually found in diploid cells. When cells have one chromosome from a pair plus a portion of the second chromosome, this is referred to as partial monosomy.

Question 26

mutagen

Answer 26

an agent, such as radiation or a chemical substance, which causes genetic mutation.

Question 27

mutation

Answer 27

the changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes.

Question 28

nondisjunction

Answer 28

the failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during nuclear division, usually resulting in an abnormal distribution of chromosomes in the daughter nuclei.

Question 29

offspring

Answer 29

the product or result of something.

Question 30

parent cell

Answer 30

A cell that is the source of other cells, as a cell that divides to produce two or more daughter cells, or a stem cell that is a progenitor of other cells or is the first in a line of developing cells.

Question 31

point mutation

Answer 31

A point mutation occurs in a genome when a single base pair is added, deleted or changed

Question 32

replication

Answer 32

the action of copying or reproducing something.

Question 33

sexual reproduction

Answer 33

Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes

Question 34

somatic cell

Answer 34

Somatic cells are the cells in the body other than sperm and egg cells

Question 35

substitution

Answer 35

the action of replacing someone or something with another person or thing.

Question 36

trisomy

Answer 36

means the affected person has three copies of one of the chromosomes instead of two

Question 37

trait

Answer 37

a distinguishing quality or characteristic, typically one belonging to a person.