In 1898 Friedrich Loeffler and Paul Frosch found evidence that the cause of the highly contagious hool-and-mouth disease in
livestock was a microscopic infectious particle. It was discovered that this particle requires a host cell to reproduce,
Which pathogen is most likely responsible for causing hoof-and-mouth disease in livestock?
A bacterium, because it is contagious
A fungus, because it infects livestock
A protist, because it is microscopic
A virus, because it requires a host cell to reproduce

explanation:

the fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus eohippus.

ans.

gregor john mendel is known for study of inheritance in pea plants. he used garden pea plant for his study, having alternative traits for various characters. he performed cross-breeding in pea plants to check how characters are transmitted between parents to offspring, such as cross between pure tall and pure dwarf plant. mendel studied the inheritance patterns in pea plants for various generations.

thus, the correct answer includes options and f).