Genetic quiz 1 half 1

What is DNA?

DNA stands for deoxyribonucleic acid. It contains the genetic code that determines inherited traits.

Where is DNA Located?

Inside the chromosome in the nucleus

Nucleotides (3 parts of a nucleotide)

1. Phosphate group: One part of the DNA backbone. 2. Deoxyribose sugar: A five-carbon sugar in DNA. 3. Nitrogenous base: A, T, C or G.

The four nitrogenous bases

A = Adenine, T = Thymine, C = Cytosine, G = Guanine

Base pairing

A - T (adenine, Thymine 2 hydrogen bonds),

T - A;

G - C (Guanine cytosine, 3 hydrogen bonds),

C - G.

What holds the nitrogen bases together.

Hydrogen bonds

What is the Sugar - Phosphate backbone held by?

The sugar-phosphate backbone is held together by covalent bonds (phosphodiester bonds).

What shape is DNA

DNA has a double helix shape, like a twisted ladder.

Determining the number of each nitrogenous base

In DNA, A = T and G = C. All four bases add up to 100%. Example: If G = 20%, then C = 20%. That leaves 60% for A and T, so A = 30% and T = 30%.

What is PURINE BASES

two nitrogen rings

What is PYRIMIDINE BASES

one nitrogen ring

What is Nucleotide

building block of DNA consists of one phosphate, one sugar and one nitrogen base

What is a gene?

A gene is a section of DNA on a chromosome that contains instructions for making a specific protein and helps determine traits.

What is Interphase

The cell grows and prepares to divide.

What is Cell division

The nucleus divides through mitosis, followed by cytokinesis, which divides the cytoplasm.

What is G1 Phase

general growth and organelle replication (copying)

What is S Phase

SYNTHESIS – the cell’s DNA is duplicated / replicated – single stranded chromosomes become double stranded

What is G2 Phase

cell prepares to divide the nucleus through mitosis and cytokinesis

What is Cancer

Cancer happens when cells divide abnormally and do not respond normally to the body's cell-cycle controls. 1. Cancer cells divide out of control 2. Cancer cells can pile up on one another

What is tumor

abnormal lump of cells

What is benign tumor

tumor that remains in one place in the body

What is malignant tumor

tumor that is capable of spreading throughout the body

What is metastasis

spread of cancer cells from the initial site to other parts of the body

What is Chromatin

DNA in a loose, thin, thread-like form inside the nucleus. It is not clearly visible as separate chromosomes.

What is Chromosome

A structure made of DNA that carries genes. After DNA replication, it consists of two sister chromatids joined at the centromere.

What is Sister chromatids

Two identical copies of a duplicated chromosome that remain attached at the centromere until they separate.

What is a diploid(2n) ?

a cell containing two copies of each chromosome. It is a Body cells = 46

What is a haploid(n)

One set of chromosomes; half the diploid number. It is a Sperm and egg = 23. When sperm (23) joins with an egg (23), they form a zygote with 46 chromosomes.

What is Mitosis

Mitosis is the division of the nucleus that produces two genetically identical diploid daughter cells.

What is the end result of Mitosis?

2 daughter cells. Both are diploid (46 chromosomes in humans). Both are genetically identical to each other and the parent cell.

In which types of cells does Mitosis occur?

Mitosis occurs in body (somatic) cells for growth, repair, and cell replacement.