Tutorial 8 : Species and varieties

Question 1

incipient species

Answer 1

a species that is starting to develop (emerging, new)

Question 2

systematist

Answer 2

a naturalist engaged in classification

Question 3

autogamous

Answer 3

engaging in self-fertilisation (the fusion of two gametes that come from one individual)

Question 4

coach dogs

Answer 4

dogs which were usually bred and trained to trot alongside carriages to protect the occupants from banditry

Question 5

cultivars

Answer 5

plants have been selected specifically by humans for their traits

Question 6

species

Answer 6

the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction

Question 7

varieties

Answer 7

appear within species due to environmental factors, demographic differences or genetic modifications

Question 8

hybrid

Answer 8

the offspring that happens because of the crossing of two different species
2 pure parental lines are crossed (2 homozygous crossed to produce a heterozygous hybrid)

Question 9

hybrid vigour

Answer 9

heterosis
refers to the phenomenon where hybrid offspring display traits that are superior to those of both parents (better growth rate, fertility, and overall health)

Question 10

selective breeding

Answer 10

you select the species that you want to reproduce
create new varieties/cultivars by changing the traits of the species that are of interest

Question 11

cross-breeding

Answer 11

mating of two different individuals from the same species or closely related species to produce offspring with desirable traits

Question 12

selection

Answer 12

identifying individuals within a population that possess desirable traits and using them as parents for the next generation
over time, repeated selection can lead to the fixation or specific traits within a population

Question 13

hybridisation

Answer 13

crossing two genetically distinct individuals, often from different varieties or cultivars, to produce hybrid offspring with desirable traits (can increase vigour and heterosis in the resulting plants)

Question 14

mutation breeding

Answer 14

inducing mutations in the DNA of plants through exposure to radiation, chemicals, or other mutagens

Question 15

genetic engineering

Answer 15

gene editing or transgenic technology, can be used to directly introduce or modify specific genes in plants to confer desired traits, such as pest resistance or improved nutritional content

Question 16

polyploid

Answer 16

heritable condition of possessing more than two complete sets of chromosomes

Question 17

vegetative reproduction

Answer 17

polyploid plants can reproduce asexually through various vegetative structure such as rhizomes, stolons, tubers, and bulbs
this method allows them to produce genetically identical offspring without the need for gametes

can occur in those varieties that are created by humans

Question 18

apomixis

Answer 18

some polyploid plants can produce seeds without fertilisation through a process called apromixis.
the ovules develop into seeds without undergoing meiosis or fetilisation, resulting in offspring that are genetically identical to the parent plant

only in wild species

Question 19

allopolyploidy

Answer 19

can also reproduce sexually by forming hybrids with other polyploid or diploid plants.
allopolyploidy involves the fusion of gametes from different species or varieties to produce offspring with a doubled set of chromosomes

only in wild species