Introduction to Cells and Genetics

Question 1

what is a cell?

Answer 1

the smallest unit of living organisms, take matter from their surroundings to perform chemical reactions to survive and divide

Question 2

how many cells are in the human body?

Answer 2

37,200,000,000,000
(37 trillion, 200 billion)

Question 3

define inheritance/heredity

Answer 3

the passing of physical or mental characteristics genetically from one generation to another

Question 4

where is heredity information stored?

Answer 4

DNA

Question 5

define gene

Answer 5

the segment of DNA sequence that codes for one protein (or one RNA molecule)

Question 6

what is the unit of heredity?

Answer 6

gene

Question 7

what is genetics?

Answer 7

the study of genes

Question 8

what is genomics?

Answer 8

the study of the genome

Question 9

define genome

Answer 9

all of the DNA in a cell (coding and non-coding)

Question 10

How many genes does an oak tree have?

a) 2000
b) 10,000
c) 20,000
d) 50,000
e) 200,000

Answer 10

d) 50,000

Question 11

what are the two processes that cells reproduce by?

Answer 11

1) sexual
2) asexual

Question 12

define asexual reproduction in cells

Answer 12

division of the cell to form two daughter cells, containing the same genetic information as the mother cell

Question 13

define sexual reproduction in cells

Answer 13

fusion of two special cells (gametes) to form another type of cell (zygote)

Question 14

Define the structure and function of genes and chromosomes

Answer 14

Genes are segments of DNA that contain the instructions for building proteins, while chromosomes are structures that organize and package DNA within the cell.

Question 15

How many cell types are found in a human body?

Answer 15

There are approximately 200 different cell types in a human body, each with distinct functions.

Question 16

How do cells differ despite having common features?

Answer 16

While all cells share essential structures like plasma membranes and organelles, they differ in function, size, shape, and response to stimuli.

Question 17

Identify the role of a fertilized egg cell in heredity.

Answer 17

The hereditary information in the fertilized egg cell determines the nature of the multicellular organism that will develop from it.

Question 18

List some examples of different cell types in the human body.

Answer 18

Examples include neurons, adipocytes, red blood cells, epithelial cells, and fibroblasts.

Question 19

How many cells are estimated to be in a human body?

Answer 19

The human body is estimated to contain approximately 37.2 trillion cells.

Question 20

What is the significance of cell division in heredity?

Answer 20

Cell division is crucial as it allows hereditary information to be passed from one generation to the next through reproductive cells.

Question 21

Discuss the importance of plasma membranes in cells.

Answer 21

Plasma membranes are essential as they are present in all cells, providing structure and regulating the movement of substances.

Question 22

Define the central dogma of molecular biology.

Answer 22

The central dogma describes the process of information flow from DNA to RNA to protein

Question 23

How many protein-coding genes do humans have?

Answer 23

Humans have approximately 20,000 to 25,000 protein-coding genes.

Question 24

What is the significance of germ cells in multicellular organisms?

Answer 24

Germ cells form gametes (sperm and egg) for sexual reproduction.

Question 25

Define diploid and haploid in the context of eukaryotic life cycles.

Answer 25

Diploid refers to having two copies of each gene (2n), while haploid refers to having a single copy of each gene (n).

Question 26

Who is Gregor Mendel and what is his contribution to genetics?

Answer 26

Gregor Mendel studied inheritance through pea plant breeding and published his results in 1866.

Question 27

What does the concept of breeding true mean in Mendelian genetics?

Answer 27

Breeding true means that offspring will consistently exhibit the same phenotype as the parents.

Question 28

How does cross breeding work in Mendelian genetics?

Answer 28

Cross breeding involves mating two different phenotypes, resulting in a mix of traits in the offspring.

Question 29

What is the outcome of self-pollination in Mendelian genetics?

Answer 29

Self-pollination can lead to progeny that exhibit the same phenotype as the parent.

Question 30

How do somatic cells reproduce in humans?

Answer 30

Most human somatic cells reproduce asexually.

Question 31

Define the terms homozygous and heterozygous.

Answer 31

Homozygous refers to a diploid organism with identical alleles for a gene (e.g., RR or rr), while heterozygous refers to having different alleles for a gene (e.g., Rr).

Question 32

How do the genotypes of the F1 generation differ from the F2 generation in Mendelian genetics?

Answer 32

The F1 generation typically shows a dominant phenotype (e.g., Rr), while the F2 generation exhibits a 3:1 phenotypic ratio of dominant to recessive traits.

Question 33

Explain the significance of dominant and recessive alleles in Mendelian genetics.

Answer 33

Dominant alleles mask the expression of recessive alleles in heterozygotes, determining the phenotype.

Question 34

Describe the concept of codominance with an example.

Answer 34

Codominance occurs when both alleles in a heterozygote are fully expressed, such as in the ABO blood group system where A and B alleles are codominant.