Genetics Terminology

Question 1

Heredity Definition

Answer 1

The passing of genetic traits from parent to offspring.

Question 2

What is Genetics?

Answer 2

From ‘genesis’, the area of biology concerned with how information in organisms is passed from parents to offspring/progeny.

Question 3

What did 19th century scientists show?

Answer 3

That there were factors within organisms that determined their characteristics and that these factors were heritable.

Question 4

What was the word “gene” used to describe?

Answer 4

These factors

Question 5

What did 20th century scientists show?

Answer 5

That these genes were made up of DNA.

Question 6

What do human cells contain?

Answer 6

46 DNA molecules (chromosomes) with approximately 23,000 genes.

Question 7

What is understood today?

Answer 7

That genes are segments of a DNA molecule that influence or directly code for specific traits.

Question 8

What is a chromosome made of? What does it contain?

Answer 8

-Made of DNA and protein.
-Contains genes

Question 9

What are genes?

Answer 9

Heritable factors that control specific characteristics.

Question 10

What are alleles?

Answer 10

Different forms of a specific gene.

Question 11

What is a gene locus?

Answer 11

The specific position of a gene on a chromosome.

Question 12

What do all individuals of a species do?

Answer 12

Carry the same genes at the same loci on the same chromosomes.

Question 13

Where are chromosomes contained?

Answer 13

In the nucleus of all eukaryotic cells.

Question 14

What do chromosomes vary widely in?

Answer 14

Shape, number and size.

Question 15

How do chromosomes exist in multicellular organisms?

Answer 15

In sets

Question 16

What is contained in a haploid nuclei?

Answer 16

One of each chromosome type.

Question 17

In humans, how many chromosomes do haploid cells contain?

Answer 17

23 chromosomes

Question 18

What are haploid cells?

Answer 18

Sex cells (gametes) that fuse together during sexual reproduction - egg and sperm.

Question 19

What does “haploid” mean?

Answer 19

“Half” of a full set of chromosomes.

Question 20

What do diploid nuclei contain?

Answer 20

Two of each chromosome type (and so 2 copies of each gene)

Question 21

In humans, how many chromosomes do diploid cells contain?

Answer 21

In humans, diploid cells contain 46 chromosomes (2 x 23).

Question 22

What happens during fertilization?

Answer 22

Haploid sperm and egg fuse in fertilization to produce diploid zygote, which then divides by mitosis to form embryo.

Question 23

What are diploid cells?

Answer 23

Body cells (somatic cells)

Question 24

What do males only have?

Answer 24

One copy of each gene on the X and Y sex chromosomes.

Question 25

What do eukaryotic cells contain?

Answer 25

Different types of chromosomes with different genes.

Question 26

What do chromosomes differ in?

Answer 26

Length and position of the centromere.

Question 27

How many different types of chromosomes do humans have?

Answer 27

23

Question 28

What are the different types of chromosomes that humans have divided into?

Answer 28

- 22 pairs of Autosomes (1-22). - 1 pair of Sex Chromosomes (23).

Question 29

What does each chromosome carry?

Answer 29

A different set of genes in a specific order.

Question 30

What is the location of each gene on the chromosome called?

Answer 30

The gene locus.

Question 31

What is a fundamental feature that defines a species?

Answer 31

Chromosome number

Question 32

What do all members of a species have?

Answer 32

The same chromosome number

Question 33

When does chromosome numbe tend to be conserved?

Answer 33

Across millions of years of evolution.

Question 34

In rare cases, what can happen?

Answer 34

Chromosomes can fuse together or split to change chromosome number of a species.

Question 35

During human evolution, what happened?

Answer 35

Two ancestral ape chromosomes fused to form modern day Chromosome 2 (as a result, humans have 23 types of chromosomes, while ape species have 24.

Question 36

Where are genes distributed?

Answer 36

Amongst an organism's chromsomes.

Question 37

What is the location of a gene on a chromosome called?

Answer 37

The locus of the gene

Question 38

What do all members of a species have?

Answer 38

The same chromosome number with the same genes in the same loci along their chromosomes.

Question 39

What is a genome?

Answer 39

The whole genetic information of an organism.

Question 40

What does the genome consist of in humans?

Answer 40

46 chromosomes in nucleus plus mitochondrial DNA

Question 41

What does the genome consist of in plants?

Answer 41

Chromosomes in the nucleus plus DNA in the mitochondria and chloroplasts.

Question 42

What does the genome consist of in prokaryotes?

Answer 42

Much smaller genome consisting of DNA in a circular chromosome and any plasmids.

Question 43

When did the Human Genome Project begin and what did it produce?

Answer 43

The Human Genome Project (HGP) began in 1990 and produced a full copy of a human genome in 2003.

Question 44

All human genomes vary due to what?

Answer 44

SNPs

Question 45

What is identical among all humans?

Answer 45

99.9% of the genome

Question 46

Public/private competition and collaboration drove incredibly rapid what?

Answer 46

Biotech research and development

Question 47

What did HGP produce?

Answer 47

A vast set of data in the form of the approximately 3.2 billion base letter sequence of human DNA

Question 48

What are scientists still in the process of?

Answer 48

Decoding these sequences to ID specific genes

Question 49

How many genes were identified?

Answer 49

Approximately 23,000 genes (much fewer than predicted)

Question 50

What was discovered?

Answer 50

Much of the genome is NOT transcribed

Question 51

What were highly-repetitive sequences originally called? Why?

Answer 51

"Junk DNA" but now recognized as having a number of key functions.

Question 52

What are two modes of reproduction?

Answer 52

-Asexual -Sexual

Question 53

What happens during asexual reproduction? (3 points)

Answer 53

- New individual is produced from a single parent by cell division. - Two daughters cells receive one copy of each chromosome. - Two daughter cells are genetically identical to one another and the parent cell.

Question 54

What happens during sexual reproduction? (3 points)

Answer 54

- New individual is produced from the fusion of two sex cells - Sex cells usually come from two different organisms - Offspring are not genetically identical to one another

Question 55

What are the stages of asexual reproduction in the cell cycle? What happens in each?

Answer 55

- Mitosis: Stage of the cell cycle during which the genetic material in the nucleus of a eukaryotic cell is divided equally into two nuclei. -Cytokinesis: Nuclear division -Interphase: Cell growth, normal functions, chromatin is formed.

Question 56

What are the six stages of mitosis?

Answer 56

-G2 of Interphase -Prophase -Prometaphase -Metaphase -Anaphase -Telophase and Cytokinesis

Question 57

What is cloning? (4 points)

Answer 57

-A mode of asexual reproduction -Process of forming identical offspring from a single cell or tissue -Form of biotechnology -There are ethics concerns