Brain evolution and behavioural genetics

Question 1

what is evolution?

Answer 1

the process by which living things change over time

Process and change in the genetic coding of a group of organisms from one generation to the next.

Question 2

whats natural selection

Answer 2

high survival traits are passed on

Question 3

what is meant by fitness

Answer 3

the ability to survive and contribute genes to the next generation

Question 4

what is the process of evolution

Answer 4

evolution influences the pool of behavior-influencing genes available to the members of each species

each individual’s gene initiates a unique program of neural development

experience modifies the expression of an individuals genes

the development of each individuals nervous system depends on its interactions with the environment

each individuals current behavioral capacities and tendencies are determined by it unique patterns of neural activity, some of which are experienced as thoughts, feelings, memories ect..

each individuals current behavior arises out of interactions among its ongoing patterns of neural activity and their perception of the current situation.

the success of each individuals behavior influences the likelihood that their genes will be passes on to future generations

Question 5

what did evolution lead to

Answer 5

increased human brain size

Question 6

where does englargment in the brain occur

Answer 6

Greatest enlargement occurs in the cerebrum

Subcortical structures phylogenetically older

Increase of convolutions to increase surface and processing power

Question 7

what did Gregor Mendel (1822-1884) studu

Answer 7

studies inheritance in pea plants

Question 8

Dichotomous traits:

Answer 8

always occur in one form or another

Question 9

True breeding lines:

Answer 9

always produce offspring with the same traits

Question 10

Phenotype:

Genotype:

Answer 10

Phenotype: observable trait

Genotype: the genetic material constituting the observable trait

Question 11

Gene:
Alleles:
Homozygous:

Heterozygous:

Answer 11

Gene: an inherited trait

Alleles: two genes that control the same trait

Homozygous: organisms that possess two identical alleles

Heterozygous: organisms that possess two different alleles

Question 12

where are genes located

Answer 12

Genes are located on chromosomes

Question 13

what is a chromosome

Answer 13

A threadlike structure found in the nucleus of the cell

Occur is matched pairs; each pair contains one allele which controls the given trait

Humans have 23 pairs of chromosomes

Question 14

what is the only exception of identicle pairs of chromosomes

Answer 14

sex chromosomes

Pair of chromosomes that determines sex

XY: male

XX: female

Question 15

Sex-linked traits:

Answer 15

traits determined by sex chromosomes

Question 16

what is turners syndrome

Answer 16

Single sex chromosomes (either X or Y)

In most cases, a missing X chromosomes in females

Question 17

Klinefelter’s syndrome

Answer 17

One extra female sex chromosome

Question 18

what is DNA

whats its function
what its made out of

Answer 18

A double-stranded polymer molecule which contains deoxyribose

Constitutes each chromosome

Each strand is a sequence of nucleotide bases
Adenine
Thymine
Guanine
Cytosine

Question 19

what is RNA

structure function

Answer 19

Ribonucleic acid

Also made up of nucleoids

It is a SINGLE stranded chain of polymers

Ribose-based (not deoxyribose)

Instead of thymine, it contains uracil

Usually further processed

Important for protein synthesis

Messenger and transfer RNA

Question 20

what is DNA replication

Answer 20

Very complex process

The double helix unwinds

The detached nucleoids attract their corresponding pair from the free-floating complementary bases

Errors in DNA replication result in clinical consequences

Question 21

what is mitosis

Answer 21

Making new cells in the body

Creation of two identical daughter cells from one parent cell

Question 22

what is meiosis

Answer 22

Cell division across generations

Reduced number of chromosomes (23) in each egg and sperm cell

The process ends in the formation of the gametes and zygote

Question 23

what is protein synthesis

how many stages what are they called

Answer 23

a process needed for protein production

Genes in the DNA code for different proteins, and this information is needed during PS

Also called gene expression

two stages
translation transcription

Question 24

Transcription?

Translation?

Answer 24

Transcription: transfer of genetic information on the DNA to messenger RNA

Translation: the code in messenger RNA is read transfer RNA in ribosomes which builds polypeptide chains (proteins) from amino acids

Question 25

what is a genetic mutation?

Answer 25

Changes to the DNA sequence that happen during cell division when the cells make copies of themselves Can be inherited from a parent or acquired during the lifetime Changes in nucleotide order will impact the genetic code Can be beneficial or disadvantageous

Question 26

downs syndrome associated with..

Answer 26

Most common genetic condition Born with an extra copy of chromosome 21 Occurred by chance Physical growth delay Intellectual disability Distinct facial features Low IQ Poor immune system Increased risk for other conditions

Question 27

proteus syndrome associated with

Answer 27

Ever heard about the elephant man? Mutation in AKT1 kinase in a mosaic state gene in chromosome 10 or 16 Associated with Skin, bone and tissue overgrowth Tumors all over the body

Question 28

Types of genetic conditions

Answer 28

Single gene disorders Chromosomal disorders Non-disjunction Translocation Incomplete dominance Genomic imprinting abnormalities Complex disorders with genetic component

Question 29

single gene disorders

Answer 29

Huntington's disease A neurodegenerative condition which is inherited Autosomal dominant inheritance 50% risk of inheritance HTT gene mutation prevents coding for Huntington's protein Mainly affects coordinated movement and cognitive ability Dementia like symptoms

Question 30

translocation

Answer 30

De la Chapelle syndrome (XX male) Male phenotype, but female chromosomes Role of the y chromosomes SRY gene, which was still included (translocated) during cell division Can be like a normal male, but also can have anomalies in the internal and external genitalia Testosterone treatment

Question 31

incomplete dominance

Answer 31

Tay-Sachs disease Destruction of nerve cells in the CNS Apparent very early in development (6 months) Excessive startle response, losing the ability to crawl, seizures, hearing loss Genetic mutation of the HEXA gene on chromosome 15 Autosomal recessive

Question 32

genetic imprinting abnormalities

Answer 32

Both are caused by a deletion in chromosome 15 in the 15q11-q13 region (knoll et al., 1989) angelmans syndrome prader-willi syndrome

Question 33

angelmans syndrome prader-willi syndrome

Answer 33

Angelman syndrome a loss of maternally inherited genes Mental retardation, sexual development deficiencies, hyperphagia, obesity, sleep disorders, seizures, ataxia, laughter outbursts Occurs in 1 of 15,00 births Prader-Willi syndrome Loss of paternally inherited genes Excessive appetite, restricted growth, weak muscles, learning difficulties, lack of sexual development, behavior challenges

Question 34

multiple allele inheritance

Answer 34

More than two alleles on the chromosome Common conditions ABO blood type Breast cancer Muscular atrophy Cystic fibrosis Schizophrenia ?

Question 35

The three classics: schizophrenia

Answer 35

Mental health condition where people may see, hear or believe things that are not real Polygenetic 21 and 23 chromosomal pairs implicated (cow, 2007) DISC-1 gene (walsh et al, 2007) Environmental impacts on gene expressions

Question 36

The three classics: Alzheimer's disease

Answer 36

A progressive condition Symptoms develop gradually over many years and become more severe It affects multiple brain functions, mainly memory APOE-e4 gene identifies as a risk gene Affects the production and processing of beta amyloid proteins

Question 37

The three classics: autism

Answer 37

Development disability caused by difference in the brain association with social communication and interaction deficits, and restricted or repetitive behaviors or interests Also polygenetic (more than 100 genes identified) Involvement of multiple genetic loci; interacting genes Twin studied most informative However, some argue that the evidence is still limited (meyrs et al., 2020)

Question 38

Genetics of psychological differences

Answer 38

Twin studies Monozygotic vs dizygotic twins Minnesota study of twins reared apart (Bouchard et al 1990) Even if raised apart mono twins remained very similar in terms of cognitive ability and personality, temperament leisure time interest However Also see; Twin Studies in Psychiatry and Psychology: Science or Pseudoscience (Jay, 2002)

Question 39

the human genome project

Answer 39

Began in the 1990 as a massive international collaboration Aimed to compile a map of 3 billion nucleotide bases that comprise the human chromosome The aim is to link genome variations to disease and develop treatments Discovery of the human proteome Limitations: too many genes linked to one disease

Question 40

modern genetics - limitaions

Answer 40

Limitations of mendelian genetics Did not use modern techniques Protein coding genes only 1% of DNA Only 1.2% of RNA involved in protein synthesis What are the gene- environment interactions? Focus beyond genes Changes in genes and gene sequences are just one aspect of inheritance Aims to study all mechanism of inheritance

Question 41

epigenetics

Answer 41

Study of all mechanisms of inheritance Focus on phenotypic changes that do not later DNA, but regulate the gene expression Important findings Non- gene DNA controls gene expression DNA methylation and histone remodeling affect gene expression Discovery of the epigenome Role of the environment in epigenetic changes Transgenerational epigenetics

Question 42

eugenics

Answer 42

Set of beliefs and practices that in the past aimed to improve the genetic quality of a human population Stived for racial improvement via planned breeding Morally wrong So what do we need to do to avoid using science for the wrong purposes ?