bio

What is a gene?

A segment of DNA coding for a protein or trait.

What are alleles?

Alternate forms of a gene, such as B and b for eye color.

Define dominant allele.

An allele that is expressed if present.

What is a recessive allele?

An allele that is only expressed if homozygous, such as bb.

What is homozygous?

Having two identical alleles, like BB or bb.

What is heterozygous?

Having two different alleles, such as Bb.

What is a genotype?

The allele combination of an organism, such as BB, Bb, or bb.

What does phenotype refer to?

The observable traits of an organism, like brown or blue eyes.

What is incomplete dominance?

A form of inheritance where the heterozygous genotype results in a blended phenotype.

What is codominance?

A genetic scenario where both alleles are fully expressed, as in AB blood type.

Define polygenic inheritance.

Traits controlled by multiple genes, leading to continuous variation.

What are multiple alleles?

More than two alleles for a gene, such as the ABO blood groups: IA, IB, i.

What is the structure of DNA?

A double-helix structure made of nucleotides.

What are nucleotides?

The building blocks of DNA, consisting of a phosphate group, deoxyribose sugar, and a nitrogenous base.

What is base pairing in DNA?

A-T and C-G are complementary base pairs.

Describe DNA replication.

A semi-conservative process where each new strand has one original and one new strand.

Which enzymes are involved in DNA replication?

DNA helicase and DNA polymerase.

What occurs during transcription?

DNA is transcribed into mRNA in the nucleus.

What are RNA bases and how do they differ from DNA?

RNA bases are A–U and C–G, differing as uracil (U) replaces thymine (T).

What happens during translation?

mRNA codons are translated into amino acids by tRNA in the cytoplasm.

What is the outcome of linking amino acids?

They form polypeptides that become functional proteins.

What are the three main types of mutations?

Substitution, insertion, and deletion.

What are the effects of mutations?

Silent (no change), missense (changes amino acid), or nonsense (premature stop).

What can cause mutations?

Radiation, chemicals, or viruses.

What is recombinant DNA?

Inserting a gene from one organism into another.

Name an example of genetic engineering.

Insulin production or GMO crops.

What is cloning?

Producing identical copies of cells or organisms.

What does PCR stand for?

Polymerase Chain Reaction, which amplifies DNA sequences.

What are some ethical issues related to biotechnology?

Gene editing (CRISPR), designer babies, GMOs, and cloning.

What is the function of the right atrium?

It receives deoxygenated blood from the body via vena cava.

What does the left ventricle do?

Pumps oxygenated blood to the body via the aorta.

What is pulmonary circulation?

The path of blood flow from the right side of the heart to the lungs and back to the left atrium.

What are the three types of blood vessels?

Arteries, veins, and capillaries.

What role do red blood cells play?

They carry oxygen via hemoglobin.

What is systolic pressure?

The pressure during ventricular contraction.

What does the term 'hypertension' mean?

High blood pressure.

What is the first line of defense in the immune system?

Non-specific barriers such as skin, tears, saliva, and mucus.

What types of immunity do B cells and T cells provide?

B cells provide humoral immunity, T cells provide cell-mediated immunity.

What is active immunity?

Natural exposure to disease or artificial exposure through vaccination.

What is the effect of immunodeficiency?

A weakened immune response, exemplified by HIV/AIDS.